This book offers a focused and thought-provoking examination of Denis Diderot's philosophical method, with particular emphasis on what the author terms his ‘Socratean’ approach. Unlike many of his Enlightenment contemporaries, Diderot did not strive to build a unified philosophical system. Instead, he exposed the internal contradictions of the systems developed by figures such as Holbach and Helvétius. Diderot revealed the paradoxes inherent in Enlightenment thought—how, when taken to their logical end, core Enlightenment principles often undermined themselves. For instance, the belief in man as a purely natural being raises troubling questions about morality, responsibility, and the power of education: if character flaws are natural, is it just to blame or reform individuals?

Through a close reading of Diderot’s major philosophical works, especially Le Neveu de Rameau, Jacques le fataliste, Paradoxe sur le comédien, and his Salons, this study reveals how Diderot used paradox and dialogue to mirror the complex, often contradictory thinking of his age. The author argues that Diderot’s form of dialectic—marked by the repeated emergence of opposing theses rather than their reconciliation—stands closer to Kant’s unresolved antinomies than to Hegel’s system. In doing so, the book makes a modest yet sincere contribution to contemporary Diderot scholarship, honouring him as an original thinker and a passionate critic of dogmatic certainty.